A boltless split bearing pedestal type universal joint

Abstract

This invention discloses a boltless split bearing seat type universal joint, belonging to the technical field of universal couplings. It includes: a universal shaft assembly, comprising a universal shaft and a first bearing and a second bearing mounted on the universal shaft; a flange fork with a first bearing hole for mounting the first bearing and the universal shaft; and a welded fork that mates with the flange fork, having a second bearing hole for mounting the second bearing and the universal shaft; the flange fork is split along the upper plane of the split surface of the first bearing hole, the split portion including a small area of ​​the first bearing hole, this small portion forming a first bearing cap; a first split surface is formed on the flange fork, and a first stud is integrally formed on the first split surface, the first stud engaging with a fastener to fix the flange fork to the first cap.

Description

Technical Field

[0001] This invention relates to the field of universal coupling technology, specifically to a boltless split bearing seat type universal joint, which is suitable for transmission connections under high torque and high load conditions. Background Technology

[0002] Universal joints with cross shafts offer advantages such as high torque transmission, high efficiency, smooth transmission, compact structure, and significant angle compensation capability, making them widely used in metallurgy, petrochemicals, shipbuilding, and mining. The universal joint is the core component of a universal joint, and its performance directly determines the coupling's load-bearing capacity and service life. Based on the structure of the fork head, universal joints are classified into: SWC type integral fork head, SWP type split bearing cap type, SWZ type integral bearing seat type, and center-split fork head type, etc. Each of these structural forms has its own advantages and disadvantages, and all are widely used.

[0003] Combination Figures 1 to 4 As shown, the SWP type universal joint's fork head is cut open from the center plane of the bearing hole, and high-strength bolts are used to press the fork head and bearing cap together as a whole. During assembly, the cross shaft is first assembled with the bearing, then placed in the bearing hole of the flange fork head, followed by the installation of the bearing cap, and the bearing is fixed by the preload of the high-strength bolts. During assembly, the cross shaft and flange fork head do not interfere with each other, therefore there is no need to reduce the width of the fork lugs, resulting in good bearing containment and strong load-bearing and impact resistance.

[0004] However, due to the large-sized threaded holes machined in the flange fork head, the material reduction process lowers the strength of the fork head, and the threads are prone to forming fatigue sources. When subjected to large preload and working torque, which generate large axial forces, fatigue cracks may easily appear in the threaded holes inside the fork head. High-strength bolts are prone to breakage under long-term stress, posing a potential safety hazard. Summary of the Invention

[0005] 1. The problem to be solved To address at least some of the problems existing in the prior art, this invention proposes a boltless split bearing seat type universal joint, which avoids bolt breakage and improves safety in use.

[0006] 2. Technical Solution To solve the above problems, the technical solution adopted by the present invention is as follows: A first aspect of the present invention is to provide a boltless split bearing pedestal universal joint, comprising: A cross shaft assembly, comprising a cross shaft and a first bearing and a second bearing mounted on the cross shaft; A flange fork head having a first bearing hole for mounting the first bearing and the cross shaft; And a welded fork head that mates with the flange fork head, having a second bearing hole formed thereon for fitting the second bearing and the cross shaft; The flange fork head is cut open along the upper plane of the split surface of the first bearing hole, and the split part includes a small area of ​​the first bearing hole, which constitutes the first pressure cap; a first split surface is formed on the flange fork head, and an integrally formed first stud is located on the first split surface. The first stud is fitted with a fastener to fix the flange fork head to the first pressure cap.

[0007] The new structure of this invention eliminates the need for high-strength bolts and large-diameter threaded holes on the fork head. The split surface is located on one side of the bearing's split face, allowing for larger stud sizes. For example, with the SWP550 specification, the maximum thread size in existing structures is M39, while the new structure allows for a maximum thread size of M60, significantly improving the threaded connection strength. Adopting this structure reduces the risk of fatigue failure in existing fork heads and the risk of breakage in high-strength bolts, resulting in a higher load-bearing capacity and longer service life for the universal joint.

[0008] Taking into full account the matching relationship between the outer diameter of the cross shaft and the first bearing hole, the bearing has a certain thickness. It is estimated that the thickness of the bearing accounts for approximately 0.25-0.4 of the first bearing hole. Therefore, according to any embodiment of the first aspect of the present invention, the flange fork head includes most of the area of ​​the first bearing hole, and the first gland includes a small part of the area of ​​the first bearing hole, with most of the area accounting for 0.60-0.75.

[0009] According to any embodiment of the first aspect of the present invention, the lower part of the first stud is a cylindrical smooth rod section, and the upper part has an external thread section. The first stud fixes the first pressure plate to the first split surface by a first round nut, and the first pressure plate is in surface contact with the first split surface.

[0010] According to any embodiment of the first aspect of the present invention, the first bearing hole and the inner hole of the first gland are provided with a first retaining ring groove A, and the outer circle of the outer ring of the first bearing of the cross shaft assembly is provided with a matching first retaining ring groove B, so as to achieve axial positioning of the outer ring of the first bearing through the first retaining ring.

[0011] According to any embodiment of the first aspect of the present invention, the welding fork head is cut open along the upper plane of the split surface of the second bearing hole, the split portion including a small area of ​​the second bearing hole, the small portion constituting a second pressure cap; a second split surface is formed on the welding fork head, and an integrally formed second stud is located on the second split surface, the second stud being fitted with a fastener to fix the welding fork head to the second pressure cap.

[0012] Taking into full account the matching relationship between the outer diameter of the cross shaft and the second bearing hole, the bearing has a certain thickness. It is estimated that the thickness of the bearing accounts for approximately 0.25-0.4 of the second bearing hole. Therefore, according to any embodiment of the first aspect of the present invention, the welded fork head includes most of the area of ​​the second bearing hole, and the second pressure cap includes a small portion of the area of ​​the second bearing hole, with most of the area accounting for 0.60-0.75.

[0013] According to any embodiment of the first aspect of the present invention, the lower part of the second stud is a cylindrical smooth rod section, and the upper part has an external thread section. The second stud fixes the second pressure plate on the second split surface by a second round nut, and the second pressure plate is in surface contact with the second split surface.

[0014] According to any embodiment of the first aspect of the present invention, the second bearing hole and the inner hole of the second gland are provided with a second retaining ring groove A, and the outer circle of the outer ring of the second bearing of the cross shaft assembly is provided with a matching second retaining ring groove B, so as to achieve axial positioning of the outer ring of the second bearing through the second retaining ring.

[0015] According to any embodiment of the first aspect of the present invention, the first retaining ring is divided into three or four segments so that the first retaining ring can be inserted into the retaining ring groove segment by segment to achieve axial positioning of the first bearing.

[0016] According to any embodiment of the first aspect of the present invention, the second retaining ring is divided into three or four segments so that the retaining ring can be inserted into the retaining ring groove segment by segment to achieve axial positioning of the second bearing.

[0017] 3. Beneficial effects Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention abandons the high-strength bolt connection method in the prior art and adopts a structure in which the fork head body and the stud are integrally formed and fixed with a round nut. There is no need to process large-scale screw holes on the fork head, thus avoiding the weakening of the structural strength of the fork head body. At the same time, the flat contact cap and split surface design ensure the stability of the connection. (2) The split surface of the present invention is set between the split surface of the bearing and the cross shaft, which increases the installation space of the stud and can significantly increase the thread specification. Taking the SWP550 specification as an example, the thread specification can be increased from the existing maximum M39 to M60, which greatly improves the thread connection strength and reduces the risk of breakage. (3) By optimizing the structural design, this invention reduces the risk of fatigue failure of the fork head and breakage of connecting parts. At the same time, the bearing limiting structure is reliable and avoids axial movement of the bearing. This significantly improves the load-bearing capacity of boltless split bearing seat universal joints, couplings and rolling equipment, and greatly extends their service life. (4) The segmented snap ring design and the matching method of the stud and round nut of the present invention facilitate the installation, disassembly and maintenance of the universal joint, and reduce maintenance costs and workload. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a three-dimensional schematic diagram of an existing split bearing pedestal universal joint; Figure 2 This is a three-dimensional schematic diagram of the flange fork of an existing split bearing seat type universal joint; Figure 3 This is a two-dimensional front view of the flange fork head of an existing split bearing seat type universal joint; Figure 4 yes Figure 3 A sectional view along the AA direction; Figure 5 This is a three-dimensional schematic diagram of the boltless split bearing seat universal joint of the present invention; Figure 6 This is a three-dimensional schematic diagram of the flange fork of the boltless split bearing seat universal joint of the present invention; Figure 7 This is a two-dimensional front view of the flange fork of the boltless split bearing seat universal joint of the present invention; Figure 8 yes Figure 7 A sectional view along the BB direction; Explanation of markings in the diagram: 1. Cross shaft assembly; 11. Cross shaft; 12. First bearing; 121. First retaining ring groove B; 13. Second bearing; 131. Second retaining ring groove B; 2. First connecting component; 21. Flange fork head; 211. First fork head body; 212. First split section; 213. First stud; 22. First gland; 221. First retaining ring groove A; 23. First retaining ring; 24. First round nut; 3. Second connecting component; 31. Welded fork head; 311. Second fork head body; 312. Second split surface; 313. Second stud; 32. Second pressure cap; 321. Second retaining ring groove A; 33. Second retaining ring; 34. Second round nut. Detailed Implementation

[0020] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0021] like Figures 5 to 8 As shown, this embodiment provides a boltless split bearing seat type universal joint including a cross shaft assembly 1, a first connecting component 2, and a second connecting component 3.

[0022] The cross shaft assembly 1 is the core load-bearing component of the entire universal joint, playing a crucial role in transmitting power from one end connection component to the other. Its structural stability directly determines the universal joint's load-bearing capacity and operational reliability. The specific structure is as follows: The aforementioned cross shaft assembly 1 mainly consists of three parts: cross shaft 11, first bearing 12, and second bearing 13. The three parts work together to achieve flexible power transmission.

[0023] like Figure 5 As shown, the four journals of the cross shaft 11 (corresponding to the mounting positions of the first bearing 12 and the second bearing 13 respectively) have all been ground, and the surface roughness is controlled below Ra0.8μm to ensure the fit accuracy with the bearing, reduce the assembly clearance, and reduce vibration and noise during operation.

[0024] In this embodiment, the first bearing 12 and the second bearing 13 are cylindrical roller bearings or needle roller bearings (selected according to the load requirements of the actual application scenario; for example, needle roller bearings are used for smaller sizes). The bearings and the journal of the cross shaft 11 are interference-fitted, and a press-fit process is used during assembly to achieve a tight fit, preventing relative sliding between the bearings and the journal of the cross shaft 11 and avoiding accelerated wear. The outer ring of the bearing mates with the mounting holes of the subsequent first connecting component 2 and the second connecting component 3, providing flexible support for the rotation of the cross shaft 11, ensuring that the cross shaft 11 can rotate freely around its own central axis, while adapting to the angle changes between the two connecting components, and achieving smooth power transmission. In addition, the bearing is filled with high-temperature grease, which reduces frictional loss between the rolling elements and the inner and outer rings, and also acts as a sealant and rust preventer, extending the service life of the bearing.

[0025] The first connecting component 2 mentioned above, as one of the connecting ends of the universal joint, is mainly used to connect with the power source (such as a motor) or actuator (such as a drive axle) of the equipment to realize the input or output of power.

[0026] like Figure 5As shown, the first connecting component 2 includes a flange fork 21, a first pressure cap 22, and a first retaining ring 23. These three components work together to complete the installation, fixation, and positioning of the first bearing 12, while also enabling connection to external equipment. The flange fork 21 is the core load-bearing component; the first pressure cap 22 cooperates with the flange fork 21 to form a bearing mounting hole; and the first retaining ring 23 is used to axially limit the outer ring of the first bearing 12. These three components work together to form a stable connection structure.

[0027] Specifically, such as Figure 6 and Figure 7 As shown, the flange fork head 21 includes a first fork head body 211. The first fork head body 211 is manufactured using casting or forging processes, and its material matches that of the cross shaft 11. It is made of high-strength alloy structural steel to ensure sufficient load-bearing capacity and structural rigidity. One end of the first fork head body 211 is provided with a flange, on which multiple connection holes are evenly distributed for connecting to the flange of external equipment (such as a motor output shaft) via bolts to achieve power transmission; the other end forms a fork-shaped structure for mounting the first bearing 12, providing support for the assembly of the cross shaft assembly 1.

[0028] Furthermore, the first fork body 211 includes two forks, and a first split surface 212 is formed along the radial direction of either fork. The position of the first split surface 212 is designed to be located between the midpoint of the first bearing 12 and the cross shaft 11, which facilitates the assembly of the cross shaft assembly 1. Specifically, the first fork body 211 includes most of the bearing hole area, and the first cap 22 only includes a small portion of the bearing hole area. The ratio of the two areas is approximately 3 (0.75 for most of the area and 0.25 for the small portion).

[0029] For example, the cross-sections of the two fork heads can be arranged symmetrically or asymmetrically. For instance, in one case, the first fork head body 211 includes most of the bearing hole area, while the first cap 22 only includes a small portion of the bearing hole area, with a ratio of approximately 3 (0.75 for most of the area and 0.25 for the small portion). In the other case, the first fork head body 211 includes 0.6 of the bearing hole area, while the first cap 22 includes 0.4 of the bearing hole area, with a ratio of approximately 1.5.

[0030] During assembly, first place the cross shaft into the bearing hole at the bottom of the flange (welded) fork head, then install the bearing, then install the split retaining rings in sections, and finally install the bearing cover. Use the round nut to press the fork head and bearing cover into a whole, thereby fixing the bearing.

[0031] It should be noted that the first stud 213 is integrally formed on the first section 212. Compared with the traditional bolt connection method, this integrally formed structure eliminates the connection gap between the stud and the fork body, improves the rigidity and stability of the connection, avoids the risk of the stud loosening or falling off during high-speed rotation, and at the same time reduces the number of parts and simplifies the assembly process.

[0032] To control the tightness of the fit between the first pressure cap 22 and the first split surface 212 and ensure assembly accuracy, the structure of the first stud 213 is divided into upper and lower parts: the lower part is a cylindrical smooth rod section, the diameter of which matches the cylindrical screw hole of the first pressure cap 22, using a transition fit to ensure the positioning accuracy of the first pressure cap 22 and the first stud 213, avoiding misalignment after the first pressure cap 22 is assembled, thereby ensuring the coaxiality of the first bearing hole; the upper part has an external thread section, the external thread adopts a fine thread design, the fine thread has higher thread accuracy and self-locking performance, and the first round nut 24 can be used to cooperate with the external thread section to tightly fix the first fork head body 211 and the first pressure cap 22, and the tightening torque of the round nut can be adjusted at the same time.

[0033] The first pressure cap 22 and the first split surface 212 are in planar contact. The planar contact design can increase the contact area between the two, so that the pressure is evenly distributed, avoid the deformation of the component caused by local stress concentration, facilitate processing and assembly, ensure tight fit, prevent dust and impurities from entering the bearing mounting cavity, and play a certain sealing role.

[0034] What surprised the inventors even more was that, through structural optimization of the present invention, the prior art was eliminated ( Figure 1 The universal joint, with its face toothed fit, is used in the dusty, high-humidity (40%), and high-temperature (200-300℃) rolling environment of metallurgy. The meshing gaps of the face teeth easily accumulate iron oxide scale, oil, and moisture. Because there is no effective seal on the tooth surface, impurities enter and cause abrasive wear, leading to rapid scoring of the tooth surface. Corrosion and fatigue coupling significantly shorten its service life. This invention uses surface contact (friction contact), solving the problems of uneven wear of the face teeth and localized tooth chipping causing imbalance in the flange's circumferential mass distribution, resulting in severe dynamic imbalance during high-speed rotation.

[0035] Wherein, after the first fork body 211 and the first pressure cap 22 are fixed by the first stud 213 and the first round nut 24, the two cooperate to form the first bearing hole of the first bearing 12. The inner diameter of the mounting hole and the outer ring of the first bearing 12 are in a small interference fit with the bearing hole, and the outer ring is not allowed to rotate in the mounting hole.

[0036] To prevent the first bearing 12 from axially shifting during operation and ensure the stability of power transmission, this invention designs a reliable axial limiting structure: a first retaining ring groove A221 is provided at the connection between the first bearing hole and the inner hole of the first pressure cap 22, and a first retaining ring groove B121 matching the first retaining ring groove A221 is provided on the outer circle of the outer ring of the first bearing 12 in the cross shaft assembly 1. The first retaining ring groove A221 and the first retaining ring groove B121 are completely identical in size and shape and are coaxially arranged. During assembly, the first retaining ring 23 is embedded into the annular groove formed by the first retaining ring groove A221 and the first retaining ring groove B121, thereby achieving axial limiting of the outer ring of the first bearing 12 and restricting the axial movement of the bearing outer ring.

[0037] Similarly, the second bearing hole and the inner hole of the second pressure cap 32 are provided with a second retaining ring groove A321, and the outer circle of the outer ring of the second bearing 13 of the cross shaft 11 assembly 1 is provided with a matching second retaining ring groove B131, and the axial positioning of the outer ring of the second bearing 13 is achieved by the second retaining ring 33.

[0038] In this embodiment, the first retaining ring 23 and the second retaining ring 33 are divided into 3 or 4 segments, which makes the retaining rings easy to install.

[0039] The second connecting component 3, as described above, is symmetrical in structure and similar in function to the first connecting component 2. Serving as another connecting end of the universal joint, it is used to connect to another drive shaft of the equipment, enabling continuous power transmission. Its structural design is consistent with the first connecting component 2, ensuring the symmetry and uniform stress distribution of the overall universal joint structure, thereby improving the operational stability and service life of the universal joint.

[0040] like Figure 5 As shown, the second connecting component 3 includes a welding fork 31, a second pressure cap 32, and a second retaining ring 33. The assembly relationship and functional division of the three correspond completely to the flange fork 21, the first pressure cap 22, and the first retaining ring 23 of the first connecting component 2. The main difference between the welding fork 31 and the flange fork 21 lies in the connection method with external equipment: the welding fork 31 is connected to the drive shaft by welding, which is suitable for scenarios that require fixed connection and do not require disassembly, while the flange fork 21 is connected by bolts, which is suitable for scenarios that require disassembly and maintenance. The two connection methods can be flexibly selected according to actual application requirements, improving the versatility of the universal joint.

[0041] In this embodiment, the welding fork head 31 includes a second fork head body 311. The second fork head body 311 is also forged from high-strength alloy structural steel. One end of it is a fork-shaped structure for mounting the second bearing 13, and the other end is a welding end. It is firmly connected to the transmission shaft through welding processes such as submerged arc welding and gas shielded welding. The weld is inspected for flaws to ensure welding quality and avoid power transmission failure caused by welding defects (such as cracks or incomplete penetration).

[0042] Similar to the first fork body 211, the second fork body 311 has a second split surface 312 formed along its radial direction. The second split surface 312 is also located between the split surface of the second bearing 13 and the cross shaft 11. Its function is the same as that of the first split surface 212, which facilitates the assembly of the cross shaft assembly 1, improves assembly efficiency, and protects the bearing from damage. A second stud 313 is integrally formed on the second split surface 312. The structure of the second stud 313 is exactly the same as that of the first stud 213. The lower part is a cylindrical smooth rod section, which transitions with the cylindrical screw hole of the second pressure cap 32 to ensure positioning accuracy. The upper part is an external thread section, which fixes the second fork body 311 and the second pressure cap 32 through the second round nut 34. The fine thread design ensures the self-locking performance and assembly accuracy of the connection, and the integrally formed structure improves the rigidity and stability of the connection.

[0043] Specifically, the second fork body 311 includes most of the bearing hole area, while the second cap 32 only includes a small portion of the bearing hole area. The ratio of the two areas is approximately 3 (0.75 for most of the area and 0.25 for the small portion). The second fork body 311 includes two forks. Similarly, the cross-sections of the two forks can be symmetrically or asymmetrically arranged.

[0044] like Figure 8 As shown, the second pressure cap 32 and the second split surface 312 also adopt a planar contact design to increase the contact area, evenly distribute pressure, avoid local stress concentration, and at the same time play a certain sealing role to prevent impurities from entering the bearing mounting cavity. After the second fork body 311 and the second pressure cap 32 are fixed by the second stud 313 and the second round nut 34, they cooperate to form the second bearing hole of the second bearing 13. The inner diameter of the second bearing hole matches the outer diameter of the outer ring of the second bearing 13, and an interference fit is adopted to ensure that the outer ring of the second bearing 13 can rotate flexibly while avoiding wobbling and ensuring the smoothness of power transmission.

[0045] The axial limiting structure of the outer ring of the second bearing 13 is completely consistent with that of the outer ring of the first bearing 12: a second retaining ring groove A is provided at the connection between the inner hole of the second bearing hole and the inner hole of the second pressure cover 32, and a matching second retaining ring groove B is provided on the outer circle of the outer ring of the second bearing 13 of the cross shaft assembly 1. The second retaining ring 33 is embedded in the annular groove formed by the two to achieve axial limiting of the outer ring of the second bearing 13.

[0046] It should be noted that, in this embodiment, the universal joint may inevitably experience breakage of the first or second stud on the stressed side during high-speed rotation. Since the ratio of the majority to the minority area of ​​the bearing bore used in this invention is between 1.5 and 3, a bearing is fitted onto the outer side of the universal joint. Figure 8As shown, the force on the cross shaft and bearing along the fracture direction of the stud will be transmitted to most of the bearing hole area, and the bearing is blocked by the edge of the hole; and the corresponding retaining ring is set perpendicular to the rotation direction of the central axis, which can maintain axial limiting under the action of rotational inertia, effectively avoiding the problem of instantaneous breakage of the cross shaft and bearing.

[0047] The assembly method of the boltless split bearing seat type universal joint of the present invention includes the following specific steps: 1) First, place the cross shaft into the bearing hole at the bottom of the flange (welded) fork head, then install the bearing, then install the split retaining rings in sections, and finally install the bearing cover. Use the round nut to press the fork head and bearing cover into a whole, thereby fixing the bearing. 2) Assembly of the first connecting component 2: Align the first bearing 12 of the cross shaft assembly 1 with the fork-shaped structure of the first fork body 211, and fit the first pressure cap 22 with the smooth section of the first stud 213 through the cylindrical screw hole to fit the first split surface 212. Then screw the first round nut 24 into the external thread section of the first stud 213 and tighten it to the specified torque to fix the first fork body 211 and the first pressure cap 22 to form the first bearing hole. Then, insert the first retaining ring 23 into the first retaining ring groove A221 and the first retaining ring groove B121 to complete the axial positioning of the outer ring of the first bearing 12. 3) Assembly of the second connecting component 3: Using the same assembly method as the first connecting component 2, the second bearing 13 of the cross shaft assembly 1 is fitted with the second fork body 311 and the second pressure cap 32, and fixed by the second stud 313 and the second round nut 34. Then, the second retaining ring 33 is inserted to complete the axial positioning of the outer ring of the second bearing 13. 4) Overall inspection and debugging: After assembly, check the rotation flexibility of the universal joint to ensure that the cross shaft 11 can rotate freely without jamming or shaking; check the tightness of each connection part to ensure that the round nut and retaining ring are installed reliably; finally, perform dynamic balancing test to eliminate vibration during high-speed rotation and ensure that the universal joint meets the usage requirements.

[0048] When power from an external device is transmitted to one of the connecting components (such as the flange fork 21 of the first connecting component 2), the flange fork 21 drives the cross shaft 11 to rotate around its own axis. Supported by the first bearing 12 and the second bearing 13, the cross shaft 11 transmits power to the other connecting component (such as the welded fork 31 of the second connecting component 3), thereby driving the drive shaft connected to the welded fork 31 to rotate, thus realizing power transmission between the two shafts. During power transmission, because the four journals of the cross shaft 11 are perpendicular to each other, when there is a certain angle between the two connecting components (intersecting or relatively inclined), the cross shaft 11 can rotate flexibly around the bearings to adapt to angle changes, ensuring smooth and continuous power transmission. Simultaneously, the axial limiting effect of the retaining ring prevents bearing movement and ensures operational stability.

[0049] However, extensive use revealed that the universal joint of this embodiment is prone to increased vibration when accelerating to its rated speed. The reason for this is that the perfectly symmetrical fork head has a single natural frequency, leading to severe resonance at specific speeds. The asymmetrical design of this invention effectively breaks the geometric / mass symmetry, staggering multiple natural frequencies and resulting in smoother operation of the universal joint. This asymmetrical design not only meets the above usage requirements but also ensures safe and reliable operation of the universal joint at specific speeds.

[0050] Mechanical analysis was performed on the boltless split bearing seat universal joint obtained in this embodiment: with a rotation diameter of 550mm, the stud is M60, replacing the original M39 bolt.

[0051] Compared with existing technical structures: the upper and lower sections of the flange fork are set to rough contact; the bolt thread section and the bolt hole thread section are set to frictional contact with a friction coefficient of 0.15; the simulated thread parameters are set as follows: pitch diameter 36.402mm, thread pitch 4mm; the bolt nut end face and the bolt hole end face are set to frictional contact with a friction coefficient of 0.1; the cross shaft 11 and the inner hole of the bearing outer ring are set to frictional contact with a friction coefficient of 0.02; the outer circular surface of the bearing outer ring and the bearing hole of the flange fork are set to frictional contact with a friction coefficient of 0.1.

[0052] The optimized structure of this invention is as follows: the upper and lower sections of the flange fork are in frictional contact with a friction coefficient of 0.1; the round nut and the threaded section of the stud are in frictional contact with a friction coefficient of 0.15; the simulated thread parameters are set as follows: pitch diameter 57.402 mm, thread pitch 4 mm; the outer circular surface of the bearing outer ring and the bearing hole of the flange fork are in frictional contact with a friction coefficient of 0.1; the contact surface between the round nut and the upper flange fork is in frictional contact with a friction coefficient of 0.1; and the cross shaft 11 and the inner hole of the bearing outer ring are in frictional contact with a friction coefficient of 0.02.

[0053] The analysis steps and load settings are shown in the table below:

[0054] Stress comparison (von Mises stress, unit: MPa) before and after structural optimization of the present invention:

[0055] The optimized structure in this embodiment significantly reduces the maximum stress in key load-bearing components such as flange forks, bolts, and round nuts. The stress reduction under torque conditions for bolts and nuts reaches 51.3%, effectively alleviating stress concentration. In the original structure, the stress in many places far exceeded the material's yield strength. After optimization, the stress level is closer to the material's allowable range, resulting in a significant improvement in structural strength and fatigue life.

[0056] In addition, the stress on the cross shaft remained basically unchanged, and the optimization scheme did not have an adverse effect on the core transmission components; and the maximum displacement increased slightly, but it was still within the acceptable range for engineering, and the overall stiffness met the usage requirements.

[0057] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A boltless split bearing pedestal type universal joint, comprising: The cross shaft assembly (1) includes a cross shaft (11) and a first bearing (12) and a second bearing (13) mounted on the cross shaft (11). The flange fork (21) has a first bearing (12) hole for fitting the first bearing (12) and the cross shaft (11). and a welded fork (31) that mates with the flange fork (21), having a second bearing (13) hole formed thereon for fitting the second bearing (13) and the cross shaft (11); characterized in that, The flange fork (21) is cut open along the upper plane of the split surface of the first bearing (12) hole. The split part includes a small area of ​​the first bearing (12) hole, which constitutes the first pressure cap (22). A first split surface (212) is formed on the flange fork (21), and an integrally formed first stud (213) is located on the first split surface (212). The first stud (213) is fitted with a fastener to fix the flange fork (21) to the first pressure cap (22).

2. The boltless split bearing seat type universal joint according to claim 1, characterized in that, The flange fork (21) includes most of the area of ​​the first bearing (12) hole, and the first gland (22) includes a small part of the area of ​​the first bearing (12) hole, with most of the area accounting for 0.60-0.

75.

3. The boltless split bearing seat type universal joint according to claim 2, characterized in that, The lower part of the first stud (213) is a cylindrical smooth rod section, and the upper part has an external thread section. The first stud (213) fixes the first cap (22) on the first split surface (212) through the first round nut (24), and the first cap (22) and the first split surface (212) are in surface contact.

4. The boltless split bearing seat type universal joint according to claim 3, characterized in that, The first bearing (12) hole and the inner hole of the first pressure cap (22) are provided with a first retaining ring groove A (221), and the outer circle of the outer ring of the first bearing (12) of the cross shaft assembly (1) is provided with a matching first retaining ring groove B (121), and the axial positioning of the outer ring of the first bearing (12) is achieved by the first retaining ring (23).

5. The boltless split bearing pedestal universal joint according to any one of claims 1-4, characterized in that, The welding fork (31) is cut open along the upper plane of the split surface of the second bearing (13) hole. The split part includes a small area of ​​the second bearing (13) hole, which constitutes the second pressure cap (32). A second split surface (312) is formed on the welding fork (31), and an integrally formed second stud (313) is located on the second split surface (312). The second stud (313) is fitted with a fastener to fix the welding fork (31) to the second pressure cap (32).

6. The boltless split bearing seat type universal joint according to claim 5, characterized in that, The welding fork (31) includes most of the area of ​​the second bearing (13) hole, and the second pressure cap (32) includes a small portion of the area of ​​the second bearing (13) hole, with most of the area accounting for 0.60-0.75%.

7. The boltless split bearing seat type universal joint according to claim 6, characterized in that, The lower part of the second stud (313) is a cylindrical smooth rod section, and the upper part has an external thread section. The second stud (313) fixes the second cap (32) on the second split surface (312) through the second round nut (34), and the second cap (32) and the second split surface (312) are in surface contact.

8. The boltless split bearing seat type universal joint according to claim 7, characterized in that, The second bearing (13) hole and the inner hole of the second pressure cap (32) are provided with a second retaining ring groove A (321). The outer circle of the outer ring of the second bearing (13) of the cross shaft assembly (1) is provided with a matching second retaining ring groove B (131). The axial positioning of the outer ring of the second bearing (13) is achieved by the second retaining ring (33).

9. The boltless split bearing seat type universal joint according to claim 4, characterized in that, The first retaining ring (23) is divided into three or four sections so that the first retaining ring (23) can be installed into the retaining ring groove in sections to achieve axial positioning of the first bearing (12).

10. The boltless split bearing seat type universal joint according to claim 8, characterized in that, The second retaining ring (33) is divided into three or four sections so that the second retaining ring (33) can be installed into the retaining ring groove in sections to achieve axial positioning of the second bearing (13).

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